The relationship of gastric acidity to peptic ulceration has been debated for years. Volumes have been written, supported by clinical, statistical and experimental data, on the subject of the primary etiologic factors in the genesis of peptic ulceration. From the present knowledge, it is safe to assume that no one factor can be held responsible for ulcer in general. Several factors are usually operative in the causation and prolongation of the ulcerous condition; or, according to Tendeloo,1 there is a constellation of factors. Indeed, Alvarez2 reminded his readers that there may be several types of the disease in different parts of the world. It is this very complexity of causes that has been the incentive of much experimentation. The present tendency is to consider peptic ulceration as a local manifestation of systemic disease or of disease elsewhere in the body rather than as an involvement sui generis of